STEPHANOGONIA. 437 



S. Costatum (Grev.) Cleve. {Melosira costata Grev., T.M.S., 



1864, i\\, n.s., p. 77, pi. 8, f. 3-6; H.V.H. Atl., pi. 91, f. 4 and 6*), plate 

 33, figs. 889, 890. 



Valves slightly silicious, inflated convex, bordered by a corona of long 

 simple, erect, parallel spines. Diam., 1 to 1*5 c.d.m. 



Marine. Found floating in the Scheldt, on a level with Hansweert (H.V.H. ). English Coasts : 

 Yorkshire (G. Norman), Teignmouth (Cresswell !). Baltic Sea. Found also in China, Java, and 

 in Peruvian guano. 



We represent in the text (fig. 162) S. mirabile Gru/i., a very curious 

 species inhabiting Siberia. 



GENUS 107. STEPHANOGONIA EHR, 1844 Ch. Emend. 



Valves somewhat hyaline and conical or inflated in girdle view, 

 with costa? or ribs in valve view ; apices often truncate or spinous ; 

 interspaces punctate. 



Fig. 163. Stephanogonia Actinoptyckus. 



This genus only includes a few fossil species. We represent in the text 

 (fig. 163), Stephanogonia Actinopiychus (E/ir.), (Mastogotria Ehr.), found in 

 the Nottingham deposit. 



GENUS 108. PANTOCSEKIA GRUN., 1886. 



Frustules sub-cylindrical. Valves sub-circular, bearing 3-5 

 mammiform elevations arranged in a circle. Puncta excessively 

 delicate, giving the valve the appearance of being hyaline, the 

 silica of the valve being much thickened. 



